ebb

退潮、落潮

The fishing boats always leave the harbor on the ebb.

渔船总是趁著退潮时离开港口。

衰退、低潮、衰落

Team morale was at a low ebb after three straight losses.

连输三场后，队上的士气正处于低潮。

退潮、退去

As the tide ebbed, a wide stretch of mudflat appeared.

潮水退去后，露出一大片泥滩。

衰退、减弱、消退

His enthusiasm for the job slowly ebbed away.

他对这份工作的热情渐渐消退了。

起落、消长、盛衰

The novel captures the ebb and flow of a long friendship.

这本小说写出了一段长年友谊的起落。